1. Field of the Invention
The invention generally relates to the field of clocks and, more particularly, to a clock or clock having a time and date display. The clock can also be made as a clock with a wake-up function or as a radio alarm.
2. Description of the Related Art
Clocks, and in particular clocks that have date and time displays, are known. Specifically, clock radios which, after being started by a buyer, set themselves automatically to the actual time are known. In some cases, such clocks set themselves to display the actual date. However, automatic time setting, as well as automatic date setting only occurs when a time data signal transmitted by radio (e.g., the DCF77 time mark signal transmitted in Germany) at the location of the clock can be received by the clock with a sufficient level of quality. The receipt of such a time mark signal is not always guaranteed.
It is therefore apparent that there is a need for a clock that sets its time independently from the reception of a time data signal that is transmitted via radio waves.
The invention is a method and apparatus for automatically displaying a correct time and date when initially activating a clock. In accordance with the invention, after the manufacture of the clock and before it is purchased by a user, the actual time is input to the clock via an electro-mechanical interface. In the preferred embodiment, the actual date or a corresponding data set input to the clock via the electro-mechanical interface. The clock then continues to run and correctly displays the actual time. This is accomplished by using a program that is stored in memory and/or by using data necessary for correctly displaying the time that are also stored in the memory. In preferred embodiments, the clock displays time and date information.
In the clock, the data necessary for displaying the correct time, and for optionally displaying the correct date, contain data such as calendar data that is stored in the memory of the control circuit or microcontroller. In preferred embodiments, the data comprises an xe2x80x9ceternalxe2x80x9d calendar with leap year, date and time of reset from summer to winter time and vice versa.
In accordance with the invention, setting of the clock is performed after completion and before purchase by the user, such as while the clock is still in production or when the clock is delivered to a dealer (distributor) or individual store. As a result, the user is provided with the correct time and date display when the clock is initially plugged into a power grid (i.e., a grid-power) and powered up because the clock starts without the need to reset the time and date, etc., of the clock.
Particularly in countries that have several time zones, it is possible for the user to choose the desired time zone via an input to the control circuit or microcontroller. The display shows the current time applicable to this time zone, and optionally the current date.